Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
diplomatical is an adjective meaning "using or marked by tact in dealing with sensitive matters or people". It carries one recorded sense.
using or marked by tact in dealing with sensitive matters or people
“the hostess averted a confrontation with a diplomatic chenage of subject”
Definitions, synonyms and semantic relations for diplomatical come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.